Add the first app_shell_browsertest test.

apps/shell/browser/shell_browser_main_parts.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef APPS_SHELL_BROWSER_SHELL_BROWSER_MAIN_PARTS_H_
 #define APPS_SHELL_BROWSER_SHELL_BROWSER_MAIN_PARTS_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 65 matching lines @@
       extensions_browser_client_;
   scoped_ptr<net::NetLog> net_log_;
 
   scoped_ptr<content::ShellDevToolsDelegate> devtools_delegate_;
 
   // Owned by the KeyedService system.
   extensions::ShellExtensionSystem* extension_system_;
 
   // For running app browsertests.
   const content::MainFunctionParams parameters_;
+  // If true, indicates the main message loop should be run

[James Cook, 2014/04/08 16:03:49]

nit: blank line above

And +1 for descriptive comments!

[Yoyo Zhou, 2014/04/08 21:55:21]

Done.

+  // in MainMessageLoopRun. If false, it has already been run.
+  bool run_message_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(ShellBrowserMainParts);
 };
 
 }  // namespace apps
 
 #endif  // APPS_SHELL_BROWSER_SHELL_BROWSER_MAIN_PARTS_H_